1. Field of the Invention
This invention relates to a molded dried food material which can be preserved at normal temperature, exhibits favorable rehydrate property with full of voluminous feeling when rehydrated, maintaining excellent taste, color and eat feeling without permitting the shape to be collapsed.
2. Description of the Related Art
Nowadays, a lot of instant foods such as instant noodles, instant soup and the like are available in the market, and the demand for the dried food materials mainly used as ingredients for the instant foods is increasing dramatically. Accompanying with an increase in the demand, the consumers who prefer natural quality are demanding dried food materials of quality close to natural taste and eat feeling.
The dried food materials have heretofore been dried with the hot air or have been freeze-dried to contain water in amounts of no more than 8% or no more than 5%. However, the foods dried with the hot air of the former method tend to develop a brown color due to drying with the hot air and cannot maintain colors inherent within the food materials. When dried with the hot air, causing to remain no gap within plant structures due to removal of free state water and the water in a bound state condition which is bound to constitute the plant structure. Once rehydrated back upon eating, the food materials are not rehydrated back to their initial states even cooked after several to a dozen or so minutes, giving its texture with hard to chew.
As compared to the foods dried with the hot air, on the other hand, the freeze-dried foods can be suppressed from developing a brown color to some extent. When rehydrated for eating, however, the food materials tend to become too soft losing the feeling of eating inherent to the food materials. This is because, when the food material has a high initial water content, large ice crystals developed during the freeze-drying process causing to damage the plant structure. When rehydrated back for eating, causing the food material to become soft without producing the so-called texture to eat. Besides, the “bulk specific gravity” described as the weight per a predetermined volume, is very small and light weighted which in turn causing in difficulty handling the packaging of small unit, as given example for packaging an one serving meal unit.
Specifically for food materials having large initial water content, for example, leafy vegetables, reducing its weight to its 1/10 to 1/20 of the initial weight, becoming very light weighted, when dried to remove most of all water contained within. This light weight becomes a barrier against the packaging in a small unit. When a dry product is produced while maintaining the shape, the voids increase while the weight decreases, and a “bulk specific gravity” decreases. This state becomes conspicuous in the case of the freeze-dried product. When the food material of a s mall unit is packaged in this state of condition, it will cause the dried products to float during process of packaging with troubles such as adhesion to the packaging material due to static electricity and biting at the time of sealing causing further inconvenience for production process.
When put to the rehydration, further, the rehydrated dried product and the freeze-dried product maintain the same sizes as when they are dried or are swollen to some extent. Besides, these products are very brittle since no treatments have been performed to prevent its shape from collapsing. Therefore, the products tend to lose its shape when they are shipped in bulk, and cannot hold the shape even when they are treated during the mold process. Besides, the products involve many problems such as difficult preservation at normal temperature.
Through the air drying method or the freeze-drying method alone as described above, unable to obtain a molded dried food material which can be preserved at normal temperature, exhibiting good rehydrating property without permitting the shape to be collapsed. Besides, the dried food materials obtained by the above methods do not retain its taste, color or eat feeling, not giving satisfaction to the customer preference. Therefore, it is assigned duty for professionals in this field to research and develop molded dried food materials which can be preserved at normal temperature, exhibit good rehydrating property, and retain excellent taste, color and eat feeling.
JP-A-10-309161, JP-A-6-153782 and Japanese Patent No. 2902231 disclose the inventions that try to solve the above problem. The inventions disclosed in these patent documents are all concerned to a combination of the air drying method and the freeze-drying method. More specifically, these inventions are related to dried food materials such as vegetables obtained through air dried and, then, through the freeze-drying, in an attempt to develop dried food materials having good rehydrating property while retaining its excellent taste, color and eat feeling.
JP-A-6-261679 teaches an invention related to a molded dried food material obtained by molding the food material by using a paste followed by freeze-drying. According to this invention, the once molded state is maintained to suppress the collapse of shape to some extent.
Further, JP-A-3-172152 discloses an invention related to a molded dried food material obtained by mixing the food material with a saccharoidal substance such as sugar, and compression-molding the dry product thereof. This invention provides a molded dried food material having its excellent color, eat feeling and taste.
However, the dried food materials disclosed in JP-A-10-309161, JP-A-6-153782 and Japanese Patent No. 2902231 are not provided with taste, color and eat feeling to a degree that satisfies the liking of the consumers in these days, and have not, either, been put to the treatment for preventing the collapse of shape or to the molding treatment, and cannot be said to be satisfying the consumer's requirements.
The molded dried food material disclosed in JP-A-6-261679 is not for improving the taste or the color, and is the one that is molded without being compressed or pressed. Therefore, the molded dried food material does not have a favorable rehydrating property.
Further, the molded dried food material disclosed in JP-A-3-172152 is compressed to be molded with a pressure of as large as about 200 kg/cm2 causing the structure within the plant to be destroyed and the food is not expected to rehydrate back quickly, even after the hot water is poured on. Besides, no added treatment performed after the compression molding and, hence, the molded state is not maintained to a sufficient degree.
As described above, there has not yet been provided a molded dried food material that can be preserved at normal temperature, that has favorable rehydrating property, excellent taste, color and eat feeling, and not permitting the shape to be collapsed. Therefore, it is an urgent issue imposed for professional in this field to provide the above-mentioned dried food materials for the consumers.